[Margaret Thatcher] was the invisible hand behind it. Without that, there'd be no Trainspotting and no Filth.

Choose life … I chose not to choose life. I chose something else. And the reasons? There are no reasons. Who needs reasons when you’ve got heroin?

I think there is a natural thing that you feel when you've written something taboo because you just don't want to expose the people you're close to.

We were looking for someone who could get the film [Filth] made at that kind of level, with the finance we wanted, and we spoke to a lot of people. When I met James [McAvoy] in the Soho Hotel with Jon Baird, the director, he looked about ten years old. I thought there's no way he's going to be a forty-year-old divorced alcoholic cop. I thought, really lovely guy, I'll let him and John talk and see if they get on.

You have to let people express themselves in the way that they need to express themselves. You have to express yourself in any way possible, provided you're prepared to live with the consequences.

I love doubt in a woman. It's nearly as sexy as determination.

When two people were in love you had to leave them to it. Especially when you weren't in love and wished that you were. That could embarrass. That could hurt.